Pulsar 3: Significant peaks, well above the noise 2: Faint vertical lines, signal spanning all frequencies (broadband) 2: Faint vertical lines, signal spanning the whole time of observation 2: A bell curve-shaped DM, with a best fit of 33.9, which puts it well within the galaxy.

1: Standard deviation bar is almost as big as the maximum signal; the noise is almost as strong as the ‘pulse’ Noise 1: There is no broadband signal 1: No signal appears at a constant phase 1: There is a peak in the DM, so it’s the right shape; however, this DM is too high for this direction

3: This peak extends well above the noise 3: The pulse appears across all frequencies, and though the signal appears to fade high and low frequencies, that is a processing artifact, and you can see that it is still present. Pulsar 3: Although there are breaks in the signal (vertical gaps), that is because the pulsar is nulling. The signal always appears at the same phase. 3: The DM curve has a strong peak, and it is not too high for this direction, although the x-axis scale is extended

3: The signal is broadband. 2: There is a peak, but it does not look great compared to the baseline. 3: The signal is broadband. RFI 1: Too bad! This signal has a DM peak ofzero, meaning it is RFI. If the DM is around zero, that means it cannot be a pulsar 1: The signal appears suddenly and disappears suddenly. If this were a pulsar coming into the beam, it would fade in.

3: The pulse is bright, although the curved baseline noise is a bit suspicious. RFI 1: Oh no! The signal only occurs in one sub-band, meaning it is narrowband emission, which means it cannot be from a pulsar. 1: The DM does not have a definite peak, meaning it is not coming from a specific place in the sky. 3: The signal is clearly visible at the same phase for all 2.5 minutes.

3: Many pulses appear at the same DM, making a peak in this histogram. 3: The signal-to-noise ratio is highest at a particular DM, making a peak. 3: Many pulses appear at the same DM, making a peak in this histogram. 3: Several signals at the same DM (horizontal location on plot) that have characteristic tapered shape, suggesting all signals came from the same place in space. Pulsar

1: The number-of-pulses histogram confirms that most pulses have zero DM. 1: The S/N histogram confirms that most of the signal strength has around zero DM. 1: These pulses line up horizontally, but they start at a DM of zero, meaning they cannot come from space. They are also spread out across many DMs, so this could be from not be a pulsar, as that pulsar would have to be many places in space at once. RFI

2: The S/N ratio at the pulse’s DM, around 37, is higher than it is elsewhere, though not much higher. 2: Although we only see one pulse in the time domain at a DM of about 37, the software sees more. Candidate 2: There is a single pulse that peaks at a particular DM, giving it the characteristic tapered shape.

1: The signal strength is approximately the same at many DMs. 1: There are the same number of pulses at several DMs, leading to multiple peaks. 1: The signal strength is approximately the same at many DMs. 1: The streaky, vertically linear appearance of this signal means it is not coming from a particular point in outer space. Note that the y-axis of this plot, and of many SPPs, doesn’t go down to zero. Each plot shows a different range. You have to look at all plots to find out whether a signal at a particular time (a particular place on the x-axis) originated at zero DM. This one did. RFI?

1: There are not a lot of pulses at a given DM 1: There are not a lot of pulses at a given DM. The largest number of pulses is 2. 1: The signal is not any higher at one DM than at any other DM. 1: There are no pulses. Just tiny signals at many DMs. Noise